This short note pre-registers a falsifiable prediction of the Geometric Relay Programme (GRP) for the forthcoming UNIONS weak-lensing cosmological results. The UNIONS collaboration has released its first weak-lensing shape catalogue over approximately 3, 500 square degrees of the northern sky, containing 62 million galaxies with an effective source density of 4. 96 arcmin^-2. Companion UNIONS papers are expected to provide cosmological constraints on the structure-growth parameter S8 = sigma8 sqrt (Omegaₘ/0. 3). The GRP prediction is registered before the publication of those UNIONS cosmological results. It is based on the CRT-01 and P4 predictions of the GRP, built on the Entangled Relativity action of O. Minazzoli. In this framework, the scalar relay sigma mediates a dynamical coupling between matter and geometry, producing a saturation of the strong branch outside the strictly adiabatic regime. The pre-registered prediction is: S8 (UNIONS) in 0. 74, 0. 80 as a strong-success interval, consistent with the compressed growth amplitudes reported by KiDS and DES. A weak-success outcome is defined as S8 (UNIONS) 0. 81, statistically consistent with Planck and inconsistent with the GRP prediction interval. The S8 prediction interval is obtained by propagating the P4 saturation ratio eta0 (z=1. 3) /eta0 (z=0. 4) in 0. 324, 0. 785 through the lensing kernel integral for a Stage-III survey depth, using the effective relation S8 ~ sigma8, Planck sqrt (eta0, eff). The mapping is documented in CRT V3, section 10. 3. This note does not claim confirmation of the GRP. It fixes a falsifiable prediction before the relevant UNIONS cosmological results are known. No parameter will be adjusted after the UNIONS result.
Olivier Lane-Larquey (Thu,) studied this question.